中文摘要：

LADCP（Lowered Acoustic Doppler Current Profiler）的底跟踪速度为获取全水深绝对流速剖面提供了多个参考流速。然而,不同底跟踪参考流速得到的绝对流速剖面结果却不相同。针对该问题进行了分析,结果表明：底跟踪观测的样本数及其在总流速观测样本中的比例随着离底高度的增加而减小;由于观测误差存在,底跟踪观测样本得到的流速剪切和所有流速观测样本得到的流速剪切并不相等,从而导致不同底跟踪参考流速得到的绝对流速结果不同。

英文摘要：

The LADCP （Lowered Acoustic Doppler Current Profiler） Bottom Track （BT） provides several reference velocities for shear integration to get the whole-depth absolute velocity profile of sea water. However, the resulting absolute velocity profiles are different for different BT velocities. The reason was analyzed. It was found that the sample number of BT velocities and its ratio to total samples become smaller at depths closer to the bottom. Due to sampling error, the shear of bottom track samples differs from the shear of total samples, and thus the whole-depth absolute velocity profiles are different as referring to bottom absolute velocities at different depths.